Colored concrete or other cementitious products are popular for many uses, such as walkways, patios and retaining walls for both residential and commercial uses, and also precast items such as blocks, pavers, roof tiles, colored mortar, and wall structures for commercial buildings. In some applications, the color is applied to the cementitious product as a dry powder or pigment onto the wet cement. In other applications, pigment (either as a dry powder or a liquid) is added to the cement mixture as it is being mixed with water, aggregate, etc. in a vessel, such as a portable cement mixer or a ready-mixed concrete truck.
The resulting colored material is deposited in the desired location (i.e., job site or factory) from the mixing vessel. A portion of the material, however, remains attached to the vanes, fins or other inside surface of the vessel. This colored residue must be removed from the inside of the vessel before a subsequent batch of concrete can be made, as any colored reside will partially color the subsequent batch, resulting in an off-color product. Typically, the colored residue is removed by hand scraping and then rinsed out with large volumes of water. The more solid colored residue (e.g., the initial removal of the colored material from the vessel) may be dumped and left to harden. The colored rinse water, however, must be disposed in an environmentally safe manner, which generally is by collection in licensed water collection pits. Care must be taken that essentially all color is removed from the vessel; such as rinse process often uses 300 or more gallons of rinse water.
The present disclosure provides systems, methods and compositions that are a benefit to the environment, by reducing the amount of clean rinse water needed to clean the vessel and by reducing the amount of dirty rinse water resulting from rinsing colored concrete. Additionally, the disclosure provides systems, methods and compositions that reduce the time needed to load a subsequent concrete batch in a vessel, resulting in cost savings.